"Roots" is a sweeping claim much advanced these days, as often as not encompassing popular music that only aspires to be. In the true definition, the roots are the stuff deep in the soil, the sort of thing that's not growing in plain sight; you have to dig for it. The two recordings up for discussion comprise what most listeners would have understood immediately to be folk music before that perfectly serviceable phrase got attached to self-written, usually inward-gazing songs composed on an acoustic guitar.

Traditional music is not quite extinct in its natural environment but is definitely an endangered species. Neither of these albums is a product of the field. In that sense, as the distinction goes, it documents performers of folk music, not folk performers as such (though a partial qualifier should be attached to Hog-Eye Jason Cade, who grew up in rural North Carolina amid fiddlers, including his mother; these days, however, he teaches at the University of Georgia School of Law). For at least a century, the music's survival has depended upon revivalists as much as upon native artists. By now self-consciously folk-derived musical art has its own complex history that sometimes intersects, as I know from personal experience, with the authentic tradition it has sought to imitate and perpetuate.

The revival in motion in this second decade of the 21st century takes its inspiration from its celebrated predecessor in the mid-1900s. After the fad faded, those who stayed true to its vision grew ever better at doing it. The fiddle, which had been at the center of much of the American tradition but absent from most revival performances, took its rightful place as a leading instrument.

By any reckoning Allison de Groot & Tatiana Hargreaves and Hog-Eyed Man (Jason Cade & Rob McMaken) are among the most able artists on the current oldtime scene. Their music looks back without being merely derivative, no doubt because they possess the skill and imagination -- not to mention boundless affection -- to make it their own. Hearing de Groot/Hargreaves and Hog-Eyed Man's way with "Farewell Whiskey" and "Wounded Hoosier," respectively, I can only feel a certain humble gratitude that my ears found their way to them.

Allison de Groot & Tatiana Hargreaves is two-thirds instrumental and one-third song. Though some of the titles (e.g., "Eighth of January," "Cuckoo's Nest," "Buffalo Gals") may be familiar, the arrangements are bracingly original. I almost didn't recognize the last of these, making it delight and surprise. DeGroot plays banjo on all cuts, Hargreaves fiddle on all, banjo on two. Both sing, sometimes in playful harmony as on the light-hearted "I Don't Want To Get Married," while the grim ballad "Willie Moore" is infused with all the dread and grief it merits.

Over the course of the century or so that mountain music has been available on commercial recordings, plenty of female duets and bands have made their mark, from the Coon Creek Girls to Hazel & Alice to Anna & Elizabeth. These two young women, though, don't sound quite like any of them. Theirs is an approach suited to the new century while not of that century, putting forth irony and humor on one side and commitment and sincerity on the other even as they skip, with the lightest of feet, across time.

I have reviewed the three previous Hog-Eyed Man releases (most recently 3 on 25 March 2017). This is the first to be identified not with a number but with an actual name, which plays off the title of an influential 1950s Tradition anthology of field recordings, Instrumental Music of the Southern Appalachians, which was many folkniks' introduction to same. On Old World, Cade (fiddle) and McMaken (lap dulcimer, guitar, mandolin) are joined here and there by four other musicians, including the prominent folksong collector and performer Art Rosenbaum for the one vocal (on "Cumberland Gap," also the album's single standard number) of the 19 cuts.

The new disc continues the Hog-Eyed approach: melody-rich fiddle tunes from the Blue Ridge Mountains and thereabouts. Even without words they're telling stories, into which you will be drawn before you know it. The arrangements work -- seemingly effortlessly even as they bear all the weight that history has placed upon them -- to afford the numbers a kind of otherworldly quality.

Each time I have reviewed a Hog-Eyed Man recording, I've struggled for words to express its peculiarly overwhelming impression. Each time, I am frustratingly reminded that music dwells in a realm apart from the one to which words are meant to connect us. Moreover, perhaps significantly, Cade and McMaken are not picking these up from the usual sources: old 78s spawned in the early years of commercial country music. Rather, they're inheriting them from the ghosts, so to speak, of non-professional musicians who in their lives carried a tradition spanning decades and centuries. As the title suggests, most can be traced to England, Scotland and Ireland.

There is a generous near hour of such. It is unceasingly enthralling. As always, the roots are long and deep, and they well up from -- or so it is possible for an awed listener to imagine -- something like sacred space.